Every wireless communication device includes an antenna in some form or configuration. An antenna is designed to launch an electromagnetic signal with certain desired characteristics including, for example, direction of radiation, coverage area, emission strength, beam-width, and sidelobes, among other characteristics. Antennas are available in many types. Each type generally includes a conductive metallic structure such as wire or metal surface to radiate and receive electromagnetic energy. Common types of antennas include dipole, loop, array, patch, pyramidal horn connected to a waveguide, millimeter-wave microstrip, coplanar waveguide, slotline, and printed circuit antennas.
Antennas may be integrally formed in microwave integrated circuits (MIC) or monolithic microwave integrated circuits (MMIC). These types of integrated antennas use transmission lines and waveguides as the basic building blocks. Conventional integrated antennas are formed on single layer substrates either on ceramics and laminates or Gallium Arsenide (GaAs) monolithic integrated circuit implementations. The transmission lines used in these applications utilize microstrip or coplanar waveguides (CPW) for their ease of fabrication and integration with active and discrete components.
Millimeter-wave microstrip antenna technology may be designed for a range of applications in the microwave electromagnetic spectrum. Millimeter-wave microstrip antennas are designed to operate in the electromagnetic spectrum ranging from 30 GHz to 300 GHz, corresponding to wavelengths ranging from 10 mm to 1 mm. Applications for these antennas include personal area networking (PAN), broadband wireless networking, wireless portable devices, wireless computers, servers, workstations, laptops, ultra-laptops, handheld computers, telephones, cellular telephones, pagers, walkie-talkies, routers, switches, bridges, hubs, gateways, wireless access points (WAP), personal digital assistants (PDA), televisions, motion picture experts group audio layer 3 devices (MP3 player), global positioning system (GPS) devices, electronic wallets, optical character recognition (OCR) scanners, medical devices, cameras, and so forth.